Multiple-unit boiler control.



E. F., Fishing. MULTIPLE. UNIT BDILER CONIROL. APPLICATION FILED nus. 4; 1914.

Patented Dem-18,1917.

I INVENTOR.

' i rs ATTORNEY IN FACT To all whom it may concern:

Emvns'r F. FISHER,

MULTIPLE-UNIT BOILER oon'rnon.

I Be it known that I, ERNEST I i FISHER, a citizen of the United. States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made. anew. I and useful Invention in Multiple-Unit Boiier Controls, of whichthe following 1s a spec1fication. This invention broadly relates to means for maintaining, or for assistinglin the maintenance of a constant ratio'between the rateofjfluid flow through a delivery main or header, andthe rate of fluid flow through each of' a number offeeder lineswhich communicate with and deliver fluid to the header, Specifically the invention relates to boiler or steam generator control. An object of the invention is'to produce 'means for controllingthedelivery of fluid,

through a feeder linein response to variations in the rate of fiuid flow through the feeder and the rate of; fluid flow through a.

header or delivery inain' with-which the feeder communicates and "which "receives fluid from other sources-'of'supply:

A further and more specific object is to produce means for controlling the operation of each of a number of boilers communicat;

"ing with and feeding a single-header, in respouse to variations in the amount of steam delivered by each boiler as cdmpared'jwith the amount of steamtraversing the header.- or the demand for steam upon theheader.

A further object is to produceia multiple unit boiler control such that all the boilers -'communicating with a header. operate togetheras a unit, or such that theamoun't of steam delivered by each boiler varies in proportion to the amount of steam delivered to the header for all demands upon the header. f If it were possible to substitute -a"single large boiler for a battery of smaller boilers, many difliculties now encountered in the operation of power plants would be eliminated, since all the operations would be centralized and each unitof area of heating surface would generate a proportional amount of the steam delivered for all yar'yin'g' de- ,mands upon the boiler. fSinCe it is lmpossible to employ a single large boiler as 'a sub; 'stitute for a battery of boilers or a 'number of single boilers", it is important to provide means for insuring that each boiler supply-- ing a common delivery header shall be so-operated that it will supply its proportional Specification of Letters Patent;

or PITTSBURGH, rnn'NsYLvAnIA, Assicnon To Gunmen! ELECTRIC comr m A oonroimrron' or new Yonx,

amount of steam for all steam demands upon the header. To accomplish this is an object of my present invention and it is attained by means of apparatus'herein described and illustrated as an embodiment of municating with a single header injwhicheach boiler is provided with an automatic Patented Dec. '18, 1917. Application filed August 4, 1914. Serial 3H0. 854,948. I i Y I mechanism for controlling its operation Portions of the header and portions of the leaderlines of each boiler are shown brokenaway for convenience of illustration, and

ofthe boilers is shown in section.

Referring now to the'drawlng by means of reference I numerals,-.the installatlon tion-includesa series ofboilers 'or generators 1, 2, and 3, each of'which is provided.

the automatic mechanism for controlling one is illustrated as an embodiment of myinvcn- Each boiler is provided with an automatic mechanism for controlling its operation.

The automatic mechanisms are diagrammatically illustrated, since various means [may be employed in carrying Out'myinVention.. The controlling mechanism for each boiler" the same as -'the mechanism illustrated in section as operatlngin COIlJllIlCtlOIl with the boiler 1 and consequently a detailed description of this mechanism only will be given.

As illustrated, the controlling mechanism consists of a fuel'feedihg hopper 6, a fuel feeding device 7, diagrammatically illus*.

trated, for feeding fuel from the hopper into,'the furnace associated with the boiler 1, and an automatic device, generally designated by the numeral 8, for .controlling .the operation of a fuel feeding means and also the-operation of other desired furnace mechanisms, as for example, 3 the forced draft mechanism of. the furnace and the damper. It will be'understood that the fuel feeding means 7 may be arranged to operate constantly during the operation of the furnace. associated with the boiler 1 and that the, controlling device may operate to accelerateor retardits operation, or that the fuel feeding means may be operated intermitted by a nozzle plug 11 located in the leader through piping 17. The mercury in the tube a .is electrically connected to a lead 18 of an circuit.

I in operation to differences in pressure occasioned by differences in fluid flow through the leader 4 and the header 5 as transmit- 4 I and a nozzle plug 12 located in the header 5.,

The difi'e'rentia] pressure device 9, as illustrated, consists of a- U-tube partially filled with mercury 13, and having the upper end ofeach leg of the tube sealed so as to produce a pressure chamber 14 which communicates with the nozzle plu l2'through piping 15, and a pressure c amber 16 whlch communicates with'the nozzle plug 11 electric circuit and forms a terminal of the An adjustable terminal 19 of the circuit projects downwardly through the pressure chamber 16 and is adapted to contact with the mercury in the tube and thereby close the circuit when the mercury rises in the/chamber 16 in response to a determined preponderance of the pressure in the chamber'14 over that existing in the cham-' nected to a lead 21of the electric circuit and the'circuitincludes a winding 22 of a solenoid. or an electro-magnet 23 adapted to move downwardly when the circuit is closed .and thereby shift a valve 24 so as to deliver :fluid under pressure from a passage 25 to a spring-restrained plunger 26 which is loveated in a cylinder 27. The valve 24 con trols delivery through a fluid discharge port 28 and a fluidinlet port 29 and is so ar rang ed that it will restrict or close the discharge port as the inlet port is opened, and, vice versa, wi

may be subjected to varyingfiuidpressures, depending upon the position of the valve 24,- and consequently upon the position of the electro-magnet- 23. -The magnet 23 is restrained by a coil spring 31. The plunger 26 is provided with a rod 32,which 1s operatively connected to the controlling lever 33 of the fuel feeding means 7, and is also the fuel feeding means, while a movement increase the effective area' of the discharge port as the inlet port is closed. With this arrangement the plunger of the plunger in the opposite direction will retard the operation of the. fuel feeding means. Itwill be understood that the valve'24 and its controlling ma'ghet'or solenoid may be'"70 so arranged that the plunger 26 will occupy The nozzle plug' ll is preferably a simple so H impact tube and consequently the pressure in-the chamber 16 is di'rectly proportional to the velocity of flow through the leader line. With such an arrangement the mercury column in'the U-tube will occupy difierent 35 positions in response to varying ratios of flow through the header and the leader, and the controlling device 8 will operate to..maintain a constant ratio between the rate of flow of the fluid traversing the header and the fluid 9 traversing the leader. and consequently will accelerate or retard the boiler so as to maintain' its output proportional to the demand for steam on the header. Inasmuch as each boiler is equipped with means similar tothe controlling mechanism 8, each leader 4 is provided with a nozzle v plug 11 which communicates through suitber 16. The terminal-19 is electrically con-v able piping with the pressure chamber 16.

of its corresponding U-tube. The plug 12 .111 the header is connected through piping 35 with the pressure chamber 14 of each differential pressure device 9 and each boiler W111 therefore be controlled in response to variations between the demand for steam on the header and the amount of steam it is delivering. Each differential pressure device. is provided with an equalizing valve 36 which when opened will place the chambers 14 and 16 in communication and will'renderi 1 the controlling mechanism inoperative.

The operation of the apparatus is as follows: Varymg demands for -steam .on the header :will occasion varying fluid velocities through the header and'consequently vary- 115 ing pressures within the chamber 14. These varyingpressuresiin the chamb'er14 will cause the mercury in the tube to fluctuate and Wlll elther open or close the electric circuit to retard or accelerate'the operation of a the boiler with which the automatic mecha n1sm communicates. When the boiler delivers its proper proportion of the steam to the header, the ratio between the velocity of flow in the communicating leader and'the I25 velocity of flow in the header willequal a determined constant and by properly adjusting the automatic controlling mechanism this constant may be maintained within close limits. In the apparatus illustrated adjustv ment may be made by changing the position of the terminal 19 with relation to the mercury in its corresponding tube. It' will'be understood that the U-tube may be provided with transparent wa1ls.so as to render the mercury visible, or that other means may be employed for indicating the variations be-' tween the velocity of How of the leaders and theheader, and that consequently manually controlled means may be employed for controlling the operation of the boilers to maintain the proper ratios of fluid flow the leaders and the header.

While I have described my invention as applied to the-control of steam boilers or generators it will be apparent to those skilled in the art that it 'is also applicable between to the control of-any apparatus delivering fluid, and that various changes, modificas tions, substitutions, omissions, and additions may be made without departing from the spirit and scope of the invention as set forth by the appended claims.

What I claim is r 1. The combination with a plurality .of fluid pressure generators delivering fluid to.

a common header, of a mechanism for each generator foreontrolling its operation,'and means for operating each controlling mechanism which is responsive to the flow of fluid from the generator to which it is appurtenant and to the total'fiow' through the header. v

2. In combination, a header, a'plurality of fluid pressure generators, leaders connecting the generators to the header, .a' mechanism for controlling the operation'of each generator, and means for operating ea'ch controlling mechanism comprising a flow responsive device in the leader to which the means is appurtenant and aflow'responslve device in the header beyond the generators'so as to be acted upon by the total flow therethrough.

3. In an apparatus of the character de-' scribed, a plurality of fluid pressure generators, a header, a separate connectlng passage between each generator and sa1d header,

a separate mechanism for controlling the operation of each generatorpand separate means responsive to variations between the "total rate of fluid flow in the header and the rate of fluid. flow ineach separate passage for separately controlling the operation of each of said mechanisms. j

4. A multiple unit boiler control, compris ing a plurality, of separate boilers, a"-header receiving steam from all of said boilers, a separate leader for connecting each boiler withsaid header, an impact tube located in the header beyond the boilers and exposed to the flow of fluid therethrough, a separate impact tube located in the leader from each boiler and exposed to the flow of fluid therethrough, a. plurality of differential pressure devices, ea'ch communicating with an impacttube, located in one of said'leaders, and all communicating-with 'theimpact tube 'loits header, an impact tube located in the header'beyond the boilers so as to be responsive to the men flow therethrough, an impact tube'loca'ted in the leader of each of the boilers, a differential pressure device for each boiler communicating with the first named impact tube and with the impact tube of the boiler to which it is appurtenant and responsive, in operation to the differential of the pressures delivered by'suchrimpact tubes, and means associated with each boiler and controlled by the operation of the device for such boiler for controlling the delivery of the fuel to its furnace.

6. In combination with a plurality of" ste'amgenerators, a header, a separate leaderconnect ng each'generator with sa1d header,-

an impact tube located in the header and subjected tothe total flow of fluidtherethrough,

an impact tube located in the leader of the generator to be controlled and subjected to the flow of fluid therethrough, a device responsive in operation to-the differential of the pressures delivered by both impact tubes,

and means controlled by said device for controlling the operation of the generator controlled.

7. The combination with a plurality of "fluid pressure. generators delivering fluid to ;a common header, of a mechanlsm for one of the generators for controlling its operation, and means for operating the controlling mechanism which is responsive to the flow. of fluid from the generator to which it is appurtenant and to thetota'l flow through the header.

In testimony whereof, I have hereunto ERNEST-F. FISHER.

Witnesses:

C. W. MCGHEE, E. W. MoCALLIsrnR.

subscribed my name this 31st day of July, 

